Projection systems are generally devices that integrate light sources, optics systems, electronics, and spatial light modulators for projecting data such as images, video, documents, and spreadsheets from computers or video devices onto walls or front or rear screens, for large-image viewing. They are especially popular among business users who give presentations as part of their job responsibilities. Newer projectors can weigh as little as a few pounds, making them well suited for business travelers. Projectors are also finding their way into peoples' homes for high-definition television (HDTV) and other home entertainment applications.
Many projection systems work by having spatial light modulators that are mirror devices, such as digital mirror devices (DMD's). The mirror devices correspond to the pixels or sub-pixels of image data to be projected by the projection systems. Each mirror device includes one tiltable mirror. The mirror tilts at very high frequency, sometimes more than 10,000 times in a single second, in order to properly display its corresponding pixel or sub-pixel of image data. However, achieving high tilting frequencies for the mirrors of mirror devices can be difficult to accomplish.